Generally, when testing, for example, a newly developed repeating installation at, for example, a factory at the time of shipment of the product, the repeating installation 100 to be tested is combined with various types of external test terminals A, B, C, D, E, F, G, H, and the like through repeating installations 110, 111, 112, 113, and the like and network media, as shown in FIG. 11A, so that data may be returned. The external test terminal B, for example, transmits test data to the external test terminal G through the repeating installation 100, the external test terminal G returns the same, the external test terminal B checks the returned result, and according to the returned result, the repeating connection function of the repeating installation 100 is verified.
At this time, the received data at the external test terminal B is compared with expected value data prepared in advance, to verify the transmission and reception functions of the repeating installation 100 and detect data errors.
In FIG. 11A, the repeating installation 100 has a line controller 101 for controlling lines, a transmitter-receiver 102 having transmission-reception paths P.sub.0 to P.sub.3, and a transmitter-receiver 103 having transmission-reception paths P.sub.4 to P.sub.7.
The line controller 101 controls the preparation of a line control table for the transmitter-receivers 102 and 103, to indicate a transmission-reception path corresponding to a destination terminal. For example, when data is transmitted and received between the test terminals B and G, the transmitter-receiver 102 is provided with a line control table (not shown) that is prepared according to an instruction from the line controller 101 and contains line control data indicating a route to the test terminal G through the transmission-reception path P.sub.5. and the transmitter-receiver 103 is provided with a line control table (not shown) that is similarly prepared and contains line control data indicating a route to the test terminal B through the transmission-reception path P.sub.2.
In the repeating installation 100, when the test terminal B sends data for the test terminal G, the transmitter-receiver 102 refers to the line control table, recognizes that the transmission-reception path of the destination is P.sub.5, adds the same to the data, and sends them to a system bus 104. Then, the transmitter-receiver 103 fetches the data and sends the same to the test terminal G through the transmission-reception path P.sub.5.
After receiving the data, the test terminal G returns it to the test terminal B. At this time, the transmitter-receiver 103 of the repeating installation 100 refers to the line control table, recognizes that the transmission-reception path of the destination is P.sub.2, adds the same to the data, and sends them to the system bus 104. Consequently, the transmitter-receiver 102 fetches the data and sends it to the test terminal B through the transmission-reception path P.sub.2.
In this way, the terminal B refers to results of the returned and received test data, to verify the repeating function of the repeating installation 100, and compares the received test data with expected value data prepared in advance, to verify transmission and reception functions and detect data errors.
Conventionally, a repeating installation is tested by connecting various kinds of network media to all transmission-reception paths of the repeating installation. Recent improvements in the capacity and functions of repeating installations, however, are increasing transmission-reception paths and the kinds of test terminals, and therefore, it is impossible in terms of test facility costs and installation space costs to prepare all test facilities, i.e., all kinds of network media and all kinds of test terminals. In addition, simply connecting the transmission-reception paths of a repeating installation to network media and test terminals is insufficient to completely evaluate all of the connection functions of the repeating installation.
According to the conventional test mentioned above, the transmission-reception paths P.sub.0 to P.sub.3 and P.sub.4 to P.sub.7 of the transmitter-receivers 101 and 102 of the repeating installation 100 to be tested are connected to physical network media and test terminals, and tests are carried out. However, the number of network media installed in a testing environment and the number of test terminals connected to them are limited.
Due to this, it is impossible to test the repeating function of a repeating installation with the maximum number or a number larger than the maximum number of paths related to the line control data of the repeating installation. Although the line control data is dynamically updated at intervals of, for example, 30 seconds, it is impossible to test the repeating function under a state that simultaneously involves the maximum number of paths and the dynamic updating.
A conventional protocol test arranges and connects a repeating installation to at least two terminals that operate on different protocols, manually handles OSs that support the protocols, and carries out tests. The manual operation, however, involves troublesome works and mistakes when preparing test data and verifying the data. In addition, there are several tens of protocols, and therefore, there are some limitations on always installing a testing environment having terminals that support the respective protocols and operating their OSs.
Further, the repeating installations have a function of parallel operations of various kinds of such protocols. Testing such function manually as mentioned above, however, involves protocol interference tests that may differ every time, and, in addition, it is difficult to reproduce a fault.
If a terminal is provided with a test tool for every protocol, the number of development processes will be increased because tool developing environments differ from each another depending on the OS that supports the protocol, and therefore, it is possible to prepare only same test tools and it is difficult to test all protocols.
A conventional data test transmits test data from a sender terminal through a repeating installation to be tested, returns the test data from a receiver terminal, and confirms the returned test data at the sender terminal.
Due to data congestion in network media and the repeating installation, however, the test data is sometimes abandoned, and the probability of abandoning the test data is doubled in outgoing and returning paths, compared with a one-way system resulting in a low test efficiency. If data errors occur, it is difficult to specify which of the outgoing and returning paths has caused the errors.
The conventional data test transmits test data (packets) from a test terminal, i.e., a sender terminal, returns the test data from an opposite receiver terminal to the original sender terminal, and confirms the returned test data at the sender terminal. After the confirmation, the next test data is transmitted and processed.
Accordingly, the sender terminal has overheads for the reception process and for the data confirmation process, to cause an idle time, i.e., a waiting time between the first test data transmission and the next test data transmission. Accordingly, it is impossible to test a repeating installation by substantially continuously transmitting test data thereto. Namely, it is impossible to apply a large reception load to the repeating installation.
Further, a test terminal receives test data through a physical layer (hardware).fwdarw.a driver layer.fwdarw.a dispatcher (scheduler).fwdarw.a network kernel layer. Whenever received data is handed over among these layers, an overhead for a memory copy process is involved, to deteriorate the processing performance of the test terminal and cause data congestion in each layer. This results in abandoning test data (packets), thereby deteriorating testing efficiency.
Conventionally, received protocol data is examined, as shown in FIG. 11B, by connecting, for example, a printer 120 to a test terminal G, so that the printer 120 may print the received data and an operator may examine the data by his eyes. Alternatively, the test terminal G is provided with a disk unit (not shown) to store the received test data, so that the stored data is displayed on a display unit and an operator verifies the data on the display unit by his eyes.
Accordingly, confirming data by eyes takes a long time, and since it is a monotonous work, involves confirmation oversight mistakes. It is impossible to confirm each piece of a large amount of data such as test data, and also, it is impossible to confirm data when the data is continuously transmitted and received.
Still further, when a packet loss rate is calculated according to a test data return method, it is impossible to determine which of the outgoing and the returning paths has caused a packet loss. It is also impossible for the prior art to calculate a packet loss rate according to a data outgoing path method because the total number (modulus) of transmitted packets cannot be confirmed at a receiver data terminal alone.
By the way, the prior art verifies the number of networks which can be repeated at one time by recording in a table or printing packet destination addresses received at a repeating installation for a display test. After the test, the destination addresses is calculated by reviewing the recorded or printed results. There are, however, several thousands to several tens of thousands networks, and therefore, the capacity of the recording table must be large, and a long time is needed to update the table.